The Revelation of the Triune God and its Diffusion.
I. The form which both Prophet and Apostle saw seated on the heavenly throne was of a clear, brilliant flame colour, partly red like the sardine, or, to use a modern term, the carnelian, and partly of the lighter hue of yellow amber. The truth symbolised in this appearance is thus set forth in plain terms by the Apostle to the Hebrews: "Our God is a consuming fire." The first attribute under which God presents Himself to a soul which He proposes to renew and sanctify is that of transcendently clear and brilliant holiness; He will be known in the first instance as a God with whom moral evil cannot dwell, who cannot endure, in those who approach to Him, a single stain of impurity. We cannot but grant that, awful as the spotless perfection of the Divine character is to a sinner's gaze, it is yet exceeding brilliant and glorious. The jasper and the sardine stone, although the infirm eye of man cannot bear to gaze upon them when they flash and kindle up in the sunlight, are yet of a hue exceedingly beautiful and brilliant.
II. It is the Mediator between God and man, even the Lord Jesus Christ, "which is our hope," who is here symbolised to us under the lovely and appropriate emblem of an emerald rainbow. What sweet refreshment to the aching eyeballs to rest for a while upon an emerald green, the very colour which, when the power of sight is enfeebled, is calculated to preserve it! In the existence of light, the existence of the rainbow is involved; for what is the rainbow but light reflected from the raindrops? And what is the Lord Jesus, considered as a Divine Person incarnate, but God reflected in the infirm medium of a manhood pure as crystal?
III. "Seven lamps of fire burning before the throne." Fire, we know, is a constant emblem of the Holy Spirit. The Holy Spirit is that Person in the Triune Jehovah whose office it is to sanctify the mind of man, not of one man, but of many, to abide in the Church, yet not in one local Church, but in all the branches of the Church universal. Contemplated in His office character as distinct from His essence, He is multiform; and to His multiformity the text certifies.
E. M. Goulburn, Occasional Sermons,p. 267.